Chain drives are generally used in material handling and drive technology for lifting applications and also for continuous conveyors. The compensation of the polygonal effect has been tried with different, mostly complicated compensating gears.
Practical applications to reduce the polygonal effect are hardly known due to the expensive design of compensating gears.
The chain drive designated before is known from the publication DE 15 31 307 A1 (counterpart UK publication 1,167,907). In this publication a gear wheel is driven with a varying pitch circle diameter, where a minimum radius coincides with the center of a chain pocket, while the largest radius coincides with a point at which the chain runs along the pitch circle diameter of the chain wheel.
However, with this embodiment an optimal compensation of the variations of velocities and acceleration is not possible, because the equivalent polygon needs an additional reduction of the pitch circle in the case of round steel chains at the position of the tooth middle of the chain wheel. Furthermore the known proposition does not consider that the gear tooth cutting at the concave points of intersection of the discontinuous rolling curves can not be manufactured with noncircular gear forming methods in a technically and economically feasible manner.
Also the geometric shape of the rolling curve between the points of intersection remains undefined for the individual sections. The radial und tangential velocity variations of chain drives are designated as polygon effect and constitute a problem which is well known and has been investigated many times. The chain running around the driving chain wheel results in undesirable variations of velocities and accelerations in radial and tangential directions.